Device and method for measuring retention time of AC / DC power supply

Abstract

The invention relates to an AC / DC power supply retention time measuring device and method. The device comprises an alternating-current voltage power-loss detection unit, a direct-current voltage acquisition unit, a display and man-machine interaction unit and an intelligent processing unit. The device can automatically calculate the time (the set value is adjustable) when the AC voltage power-loss detection unit detects AC power loss and the DC voltage acquisition unit detects that the DC voltage reaches the set value, namely the holding time. The device is provided with the one-key measurement button, after wiring connection is completed, the one-key measurement button is pressed down, and a time result is directly displayed on the touch display screen, so that the tedious operation of using an oscilloscope in a traditional method is avoided, and the working efficiency is improved. The specific method for measuring the retention time of the AC / DC power supply comprises the following steps of: conditioning the AC input voltage of the power supply module into 0-5V DC characteristic signals which can be input into the singlechip through the voltage transformer circuit, and transmitting the DC characteristic signals to the singlechip for processing. And the DC voltage of 0-48V DC is converted into the DC voltage of 0-5V DC through the analog quantity acquisition circuit, and the DC voltage is sent to the single-chip microcomputer for processing.

Description

Technical Field

[0001] The invention belongs to a measuring device and a method, and in particular relates to an AC and DC power supply holding time measuring device and a method. Background Art

[0002] It is mainly aimed at measuring the retention time of AC and DC power modules during the commissioning and post-commercial maintenance of nuclear power plants. An important parameter of AC and DC power modules is the retention time of the output DC power when the input power is lost.

[0003] In the control system, this parameter determines how long the power module can support the protection control circuit to continue to operate after power failure by relying on the output power provided by its own energy storage element. Specifically, it determines how many times the protection control circuit can output instructions and whether the system can be placed in a safe state. In order to ensure the function of nuclear safety, nuclear power plants will perform degradation tests on the AC and DC power modules in the DCS system power cabinet during commissioning to test the retention time of the power modules. During the maintenance period after commercial operation, this parameter will also be measured when performing AC and DC power module defect processing and aging detection to verify the performance of the power module. The current measurement technology is: manual measurement using an oscilloscope. That is, when the power is off, the oscilloscope probe is connected to the input and output ends of the AC and DC power modules respectively, and the two voltage signals are sent to the oscilloscope for acquisition. Subsequently, the AC and DC power modules are powered on with load, and then the air switch upstream of the AC and DC power module input power is disconnected. The voltage waveforms at the input and output of the AC / DC power supply module are viewed on an oscilloscope, and the hold time is calculated using the oscilloscope cursor. During the entire test process, wiring is cumbersome and the hold time calculation needs to be manually calculated on the oscilloscope, which is time-consuming and seriously affects work efficiency and, in turn, the revenue of the nuclear power plant.

[0004] With the continuous advancement of embedded technology and the continuous maturity of computer program interface development tools, it has become possible to develop various electronic products that can realize predetermined functions through hardware design and software programming. With the continuous development of communication technology, various communication methods based on bus technology, Ethernet technology, etc. can meet the different scenario requirements of developers.

[0005] There are many existing technical solutions, which basically have the following characteristics

[0006] 1) Using a dedicated test interface, the measuring device is connected to the AC / DC power module to be tested through a dedicated cable;

[0007] 2) The device has a one-touch measurement button, which can generate test results with one-touch measurement during testing;

[0008] 3) The DC output cut-off voltage setting parameters can be modified;

[0009] 4) The test data is stored in the device memory card and can be copied through the USB port;

[0010] 5) The test results are displayed on the display screen.

[0011] The shortcomings of the prior art are concentrated in the following points:

[0012] 1) The wires connecting the AC / DC power module and the oscilloscope probe interface are complicated to connect, with many contacts, which are prone to breakage during use, affecting the test efficiency;

[0013] This set of AC and DC power supply hold time measurement device uses a dedicated 4mm interface. The measurement device body is equipped with 4 4mm banana female plugs, and the dedicated test cable is 2-core. The side connected to the measurement device body uses a 4mm banana male plug, and the dedicated test cable is connected to the AC and DC power module side with a split terminal. When used, it is directly inserted into the cable terminal block to avoid the problems of loose connection and frequent disconnection of traditional oscilloscope alligator clips and probe hooks;

[0014] 2) When using an oscilloscope to measure the hold time, it is necessary to set parameters such as the oscilloscope trigger, range, and sampling period. When calculating the hold time, it is necessary to operate the oscilloscope cursor to measure the time based on the collected waveform. There are many operation steps and two or more people are required to operate, which is inefficient;

[0015] This set of AC and DC power supply holding time measurement device is divided into four parts: AC voltage power failure detection unit, DC voltage acquisition unit, display and human-computer interaction unit, and intelligent processing unit. The AC voltage power failure detection unit collects AC voltage through the circuit and sends the information to the intelligent processing unit for analysis and processing; the DC voltage acquisition unit collects the voltage of the output DC power supply through the analog acquisition circuit and transmits the information to the intelligent processing unit; the intelligent processing unit is responsible for receiving the AC voltage power failure detection unit and the DC voltage acquisition unit and signals, and calculating the time when the AC voltage power failure detection unit detects the loss of AC power and the DC voltage acquisition unit detects that the DC voltage reaches the set value (supports adjustable set value function, commonly used is 95% of the output voltage and 90% of the output voltage), that is, the holding time. The device is set with a one-key measurement button. After the wiring is connected, press the one-key measurement button, and the holding time result is directly displayed on the touch screen, avoiding the cumbersome operation of the oscilloscope and improving work efficiency.

[0016] 3) Some oscilloscopes are powered by external power supplies, which are large in size and not easy to move. Summary of the invention

[0017] The present invention aims at the defects of the prior art and provides a device for measuring the holding time of AC and DC power supplies.

[0018] The present invention is implemented as follows: an AC / DC power supply holding time measuring device, which includes an intelligent processing unit, which receives signals from an AC voltage detection unit and a DC voltage acquisition unit, and outputs results to a display and human-computer interaction unit. At the same time, the intelligent processing unit also receives external input signals from the display and human-computer interaction unit.

[0019] In the above-mentioned AC / DC power supply holding time measuring device, the display and human-computer interaction unit includes a touch display screen and buttons.

[0020] The AC / DC power supply holding time measuring device as described above further comprises two 4mm banana female connectors, which are compatible with commonly used instruments in industrial sites.

[0021] In the AC / DC power supply holding time measuring device as described above, the device test line adopts a split terminal.

[0022] A method for measuring the holding time of an AC / DC power supply comprises the following steps:

[0023] S1: Signal Acquisition

[0024] The device collects the AC input and DC output of the AC / DC power module to be tested;

[0025] S2: Start timer

[0026] After detecting the loss of AC power, the internal timer of the intelligent processing unit is started;

[0027] S3: Stop timing

[0028] The timing is stopped after the DC output voltage is detected to drop to the stop voltage;

[0029] S4: Calculation and display

[0030] The intelligent processing unit automatically calculates the holding time, displays it on the display and stores the data.

[0031] In the above-mentioned method for measuring the holding time of an AC / DC power supply, the stop voltage in step S3 can be adjusted as required.

[0032] The remarkable effects of the present invention are:

[0033] 1. Automatically realize the measurement and calculation of holding time, with high work efficiency:

[0034] This device collects AC input voltage through a voltage transformer and DC output voltage through a precision resistor voltage divider circuit to collect real-time voltage data and automatically calculate the hold time, thus avoiding the problem of low efficiency in setting triggers and calculating the hold time by time axis cursors during manual measurement using an oscilloscope.

[0035] 2. The DC output cut-off voltage setting is adjustable and has a wide range of applications:

[0036] This device can set the DC output cut-off voltage through the display screen and buttons, and can measure AC and DC power modules with different parameters;

[0037] 3. The device interface is highly versatile, and the 4mm banana interface is compatible with commonly used instruments in industrial sites (multimeters, multi-function calibrators);

[0038] 4. The device test line adopts split terminals, which can realize measurement without disconnecting the wires, and has high work efficiency;

[0039] 5. The device is small in size, light in weight, easy to move, and convenient for measuring AC and DC power modules in different cabinets. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 Hold time diagram;

[0041] Figure 2 It is the process of using the measuring device;

[0042] Figure 3 It is the working principle of the device;

[0043] Figure 4 It is the principle block diagram of the device;

[0044] Figure 5 This is a schematic diagram of the device appearance.

[0045] In the figure: 1. AC voltage detection unit; 2. DC voltage acquisition unit; 3. Intelligent processing unit; 4. Display and human-computer interaction unit; 5. USB interface; 6. Memory card interface; 7.4mm banana female plug; 8.4mm banana female plug; 9. Power supply / charging interface; 10. Touch screen; 11. Button. DETAILED DESCRIPTION

[0046] This set of AC and DC power supply holding time measurement device solves the following problems:

[0047] 1) Use an oscilloscope for measurement. Some oscilloscopes require AC power, are large in size, and require AC power at the test site, which is not convenient for movement;

[0048] 2) During the test, wires are required to connect the power module and the oscilloscope. The connection interfaces of the wires and the oscilloscope probes are not unified, making them inconvenient to connect.

[0049] 3) During operation, it is necessary to set parameters such as oscilloscope trigger, range, sampling period, etc. When calculating the hold time, it is necessary to operate the oscilloscope cursor to measure the time according to the collected waveform. There are many operation steps, and two or more people are required to operate. It takes about 360 seconds to test a power module, which is inefficient.

[0050] In addition to nuclear power plants, similar scenarios also apply to other industries.

[0051] A device for measuring the holding time of an AC or DC power supply comprises four parts: an AC voltage detection unit, a DC voltage acquisition unit, a display and human-computer interaction unit, and an intelligent processing unit.

[0052] The intelligent processing unit adopts a 32-bit single-chip microcomputer and has A / D signal acquisition function, timer interrupt function, external interrupt function, etc.

[0053] The display and human-computer interaction unit consists of a serial port touch screen, a reset button, and a one-button measurement button.

[0054] The AC voltage power failure detection unit converts the 220V AC voltage into a low-voltage AC signal through a voltage transformer, and then conditions the low-voltage AC signal into a 0-5V DC direct current characteristic signal that can be input into the microcontroller through a precision resistor, performs A / D acquisition, and connects to the AI ​​input port of the microcontroller.

[0055] The DC voltage acquisition unit detects the DC voltage of 0V-48VDC through the analog acquisition circuit, first performs voltage conversion, converts the DC voltage of 0-48V DC into a DC voltage of 0-5V DC, performs A / D acquisition, and connects to the AI ​​input port of the microcontroller.

[0056] The I / O port of the single-chip computer is set to the A / D acquisition function, and the average value, effective value, and peak-to-peak value of the AC characteristic signal are calculated. A cycle of 2ms is considered. When the average value and effective value are detected to decrease for three consecutive times, it is determined that the AC power supply is lost. At this time, the timer interrupt is turned on for timing. When it is detected that the input DC voltage reaches the set end voltage, the timing is stopped, and the time interval t from the start of timing to the end of timing is calculated. h (i.e., holding time). h Send it to the display and human-computer interaction unit for display, and at the same time send t h The time point of the measurement of the holding time is recorded in the storage system of the device in the time format of 20XX-XX-XX date and XX:XX:XX time.

[0057] The device has a USB interface and a memory card interface for inserting removable media such as a U disk and a memory card to copy test data.

[0058] The device has 2 groups of 4 4mm banana female plugs, including 2 holes for AC voltage input and 2 holes for DC voltage input.

[0059] The device uses a 5.5-2.1mm DC charging interface.

[0060] Based on the above scheme, the use process of the measuring device is shown in the attached Figure 2 , the working principle of the device is shown in the attached Figure 3 .

[0061] See the attached diagram for the device principle Figure 4 , the following is a detailed description of the accompanying drawings.

[0062] 1. AC voltage detection unit 1: used to detect AC voltage input, detect the value of AC input voltage in real time, and report the value to the intelligent processing unit;

[0063] 2. DC voltage acquisition unit 2: used for DC voltage output detection, real-time detection of the DC output voltage value, and reporting the value to the intelligent processing unit;

[0064] 3. Intelligent processing unit 3: processes the collected voltage information, calculates the holding time and stores the data;

[0065] 4. Display and human-machine interaction unit 4: Displays the calculated holding time and sets related parameters through buttons and display screen.

[0066] Appearance of the device is shown in the attached diagram Figure 5 , the following is a detailed description of the accompanying drawings.

[0067] 1.USB port 5: used to insert mobile storage media (such as USB flash drive) to copy measurement data;

[0068] 2. Memory card interface 6: used to insert a memory card to store measurement data;

[0069] 3.4mm banana female connector 7: test line interface, connected to the AC voltage input terminal of the AC / DC power module;

[0070] 4.4mm banana female connector 8: Test line interface, connected to the DC voltage output terminal of the AC / DC power module;

[0071] 5. Power supply / charging interface 9: used for power supply for normal operation of the device and providing a charging interface;

[0072] 6. Touch screen 10: used to maintain time results and parameter setting display;

[0073] 7. Button 11: Used to set the DC output stop voltage and reset function.

Claims

1. A device for measuring the holding time of an AC or DC power supply, characterized in that: The intelligent processing unit (3) comprises an intelligent processing unit (3), which receives signals from an AC voltage detection unit (1) and a DC voltage acquisition unit (2), and outputs results to a display and human-machine interaction unit (4); the intelligent processing unit (3) also receives external input signals from the display and human-machine interaction unit (4).

2. The AC / DC power supply holding time measuring device according to claim 1, characterized in that: The display and human-machine interaction unit (4) comprises a touch display screen (10) and a button (11).

3. The AC / DC power supply holding time measuring device as claimed in claim 2, characterized in that: It also includes two 4mm banana female connectors, which are compatible with commonly used instruments in industrial sites.

4. The AC / DC power supply holding time measuring device as claimed in claim 3, characterized in that: The device test line adopts split terminal.

5. A method for measuring the holding time of an AC or DC power supply, characterized in that: The following steps are included S1: Signal Acquisition The device collects the AC input and DC output of the AC / DC power module to be tested; S2: Start timer After detecting the loss of AC power, an internal timer of the intelligent processing unit (3) is started; S3: Stop timing The timing is stopped after the DC output voltage is detected to drop to the stop voltage; S4: Calculation and display The intelligent processing unit (3) automatically calculates the holding time, displays and stores the data through a display screen.

6. A method for measuring the holding time of an AC / DC power supply as claimed in claim 5, characterized in that: The stop voltage in step S3 can be adjusted as needed.

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